The title of Orson Welles' film referred to the telling of some true stories that took place in Brazil. The title of the film about the film is also true, telling the story of one of history's legendary lost films which was re-discovered in 1985 and in still in the process of being restored. Of course, it can't all be restored because it was never finished, and in the movie Welles himself admits that he had a bad habit of pursuing projects in a way that was not profitable to him.
The film Welles went to Brazil to make was part of the allied good-will efforts in World War II. Funding for the film was cut off when the head of RKO was removed and, according to Welles, as a result of this abrupt stoppage of money, the movie was cursed by a voodoo witch doctor. The curse may have worked because not only was this film never completed, but also THE MAGNIFICENT AMBERSONS, which Welles was trying to edit at the same time that he was filming in Brazil, was ruined by RKO, a member of the Brazilian cast of IT'S ALL TRUE drowned, and Welles was fired from RKO.
What we see of IT'S ALL TRUE shows Welles' artistry, improvisation, and ability to capture atmosphere by means of imagery, camera angles, and characters. We see various elements of the unfinished film including the Rio carnival and the story of four heroic fishermen.
Welles improvized the film as he went along, giving RKO the impression that he was really doing nothing at all. But his theme was the brotherhood of all people. RKO didn't "get it" and thus, perhaps, the voodoo curse extended itself to the studio itself because it eventually was sold to Lucy Ball and Desi Arnaz to become Desilu Studios and later was absorbed into Paramount Pictures. Studio "suits" need to be more careful before cutting off the work of artists -- a fact that Welles would certainly affirm.